Circular knitting machines

ABSTRACT

A needle selecting system in a circular knitting machine employing rockable selecting instruments cooperating with needles in the needle cylinder tricks, such instruments being adapted to be projected from their tricks and to have particular ones depressed selectively to miss a raising cam which the others engage, wherein the instruments are controlled by cam means so organized that instruments which through being depressed have remained at low level are rocked to project them out of their tricks before the remaining instruments raised by the raising cam have been subsequently lowered to the low level, means being provided to cause a fresh selection to be made immediately after the raised instruments descend to the level of those not raised. Thereby the needle selection and its subsequent cancellation are performed in a shorter than normal circumferential distance round the needle cylinder, this being particularly advantageous in a multifeed machine.

United States Patent lnventors Dennis Wright Aylestone; Thomas Adam, West Knighton, England Appl. No. 745,753 Filed July 18, 1968 Patented May 4, 1971 Assignee The Bentley Machine Development Company Limited Priority July 22, 1967 Great Britain 33820/67 CIRCULAR KNITTING MACHINES 4 Claims, 2 Drawing Figs.

05. Cl 66/50, s 66/57 Int. Cl D04!) D04b 15/68 Field of Search 66/50, 41, 9 (inquired), 50 (B), 42, 25, 36, 57, 14

References Cited UNITED STATES PATENTS 1,722,989 8/1929 Ames 66/50(B) 3,063,269 1 H1962 Losert et al FOREIGN PATENTS 641,866 7/1962 Italy OTHER REFERENCES l/35elgian Printed Application No. 640,878, 1/64, Bertolini, 66 0.

Primary Examiner-Wm. Carter Reynolds Attorney-Larson, Taylor & Hinds rocked to project them out of their tricks before the remaining instruments raised by the raising cam have been subsequently lowered to the low level, means being provided to cause a fresh selection to be made immediately after the raised instruments descend to the level of those not raised. Thereby the needle selection and its subsequent cancellation are performed in a shorter than normal circumferential distance round the needle cylinder, this being particularly advantageous in a multifeed machine.

CIRCULAR KNITTING MACHINES This invention is for improvements in or relating to circular knitting machines and is concerned more particularly with a procedure and mechanism for selecting needles for patterning. At the present time there is a tendency for circular knitting machines and particularly that class of machine used for knitting hose to provide as many yarn feeding stations as possible spaced apart around the needle circle, with a view to increasing the rate of productivity of the machine. Unless needle selecting mechanisms can be provided to operate at each feeding station, certain limitations of the patterning scope of the machine have to be tolerated. In other words, the increased output is only obtained at the expense of limiting the scope of the machine.

The problem encountered in seeking to provide patterning means at each feeding station of a multifeed circular machine arises from the difficulty of lack of space around the needle cylinder for accommodation of normal patterning means. The patterning means in machines for knitting hose has to determine which needles are to knit and which needles are to pass a feeding station without knitting and consequently a selection of needles for knitting and for nonknitting is very desirable, if not necessary, to be provided for immediately before each knitting station. The earliest point at which such a selection can be made is immediately after the cancellation of a previous selection and consequently space limitations have an acute influence on the possibility of providing adequately for a selection between two feeding stations. The invention seeks to provide a procedure and means whereby cancellation of an old selection and making of a new selection can be carried out over a shorter circumferential distance of the needle cylinder than has heretofore been practicable.

The invention has reference to a known system of needle selection (hereinafter referred to as a system of the type specified) in which the division of needles into knitting and nonknitting streams is effected by means of an intermediate jack beneath each needle, a selecting instrument below each such jack, a cam system cooperating with said jacks and instruments and patterning means cooperating with selecting butts on the selecting instruments. The selecting instruments are each capable of rocking movement to cause a raising butt on the instrument to project from its trick into position to cooperate with a raising cam, and they are firstly all caused to project from their tricks (thereby cancelling any previous selection) and then by selective actuation some instruments have their raising butts left projecting to engage and ride up the raising cam while the raising butts of others which have been depressed into their tricks move behind the raising cam without being lifted. The raising of selecting instruments acts through their jacks to raise their related needles into a knitting track while the needles related to instruments that are not raised follow a different (nonknitting) track. Subsequently the raised instruments are lowered by action of their jacks to join the level of those depressed into their tricks after which a subsequent selection can be made.

ln practicing the present invention arrangements are made so that the selecting instruments which have remained at low level at a given selection through being depressed into their tricks are caused to be rocked to project out of their tricks before the raised selectors (which remain projecting out of their tricks) have been lowered to the low level and a fresh selection is made immediately after the raised selecting instruments descend to the level of those which were not raised. Thus a considerable shortening of the circumferential distance needed to perform one selection of the needles, a cancellation thereof and a fresh selection of the needles, is effected. The resetting of the instruments which have remained at low level to cause them to project from their tricks is provided for by recessing or removing part of the raising cam at the level of the raising butt track of the selecting instruments remaining at low level (whose raising butts pass behind the cam), and also providing for a projecting cam to act on such low level instruments to rock them to move their raising butts out of their tricks at the recessed or cutaway part of the raising cam.

The invention comprises the provision in a circular knitting machine having a system of needle selection of the type specified of a raising cam associated with the selecting instruments and a projecting cam for acting on instruments at low level during the latter part of their passage behind the raising cam, and having the raising cam modified to permit the outward projection of the butts of the selecting instruments by the projecting cam. The raising cam may be recessed or cut away behind it at its lower trailing part to accommodate projection of the raising butts of the lower selecting instruments so that as soon as the lower instruments emerge from behind the raising earn their butts are fully projected from the tricks. ln association with such provision selecting means is provided to cooperate with all of the selecting instruments immediately after they have passed the raising cam. Conveniently the modification of the raising cam referred to consists in the formation of a horizontal groove at the back trailing part of the raising cam, such groove being slanted, in depth so as to open on to the front (i.e. the outer) face of the cam immediately before the trailing end thereof.

The provisions according to the invention thus operate so that at a given selection immediately preceding which all selecting instruments are lowered and have their butts projecting from the tricks, predetermined ones of such butts are depressed into their tricks so as to pass behind a raising cam whilst those not so depressed rise up the raising cam and are subsequently caused to pass downwardly after passing the peak of the raising cam. Before the projecting raising butts of the selecting instruments which have been raised by the raising cam reach the low level from which they commenced their ascent the raising butts of the selecting instruments which pass behind the raising cam are caused to project again from their tricks so that as soon as the raising butts of the raised and lowered selecting instruments join the low level of raising butts which have not been raised the butts of all selecting instruments are projecting (in readiness for a new selection) and the selecting instruments are then immediately acted on by further patterning means to produce a further selection of needles for knitting and nonknitting.

The modified mechanism is conveniently provided between each two successive feed points of a multifeed machine and it enables a difierent selection to be made at each feed point according to the set up of the patterning means related to each feed point in a machine having a relatively large number of feeding stations for a given cylinder diameter.

The provisions of the invention are incorporated in a needle selecting arrangement illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a developed view of some of the needle and jack operating cams of a single cylinder circular knitting machine for hosiery, as viewed from within the needle cylinder; and

FIG. 2 is a sectional view taken on the line lI-ll of FIG. 1 and showing also a section through the cylinder wall, a needle, an intermediate jack and a pattern selector.

The cam box of the machine to which the drawings relate has an arrangement of cams by which circular knitting may take place at six feeding stations and a reverse knitting cam is included at one of the stations for reciprocatory knitting. Because the invention is not restricted to any specific cam box arrangement, it will not however be necessary to explain fully the function of all the cams shown. These include a number of bolt cams many of which are withdrawn when patterning is taking place and take no part in the knitting action.

The disposition of the knitting elements can be seen in FIG. 2 in which the wall 1 of the needle cylinder is shown in section to expose one of the longitudinal slots or tricks 1a which house the knitting needles 2. Beneath each needle there is an intermediate jack 3 and a selecting instrument 4 having a selecting butt 4b at any of a number of selection levels and at raising butt 40 at a fixed level near the lower end of the instrument. A sinker is shown at 5. The knitting action is produced partly by cam action on the butts 2a of the needles and partly by cam action on either the intermediate jacks 3 or the instruments 4.

Stitches are drawn at stitch cams S1 and S6 and at any of the appropriately inserted stitch bolt cams, S2, S3, S4 and S5, which act on butts 2a of the needles. Stitches are cleared either by the needles being raised by their intermediate jacks 3 or by their selecting instruments 4 lifting the needles through the medium of their intermediate jacks.

When performed by the jacks 3, needle clearing is obtained by any one of the butts 3a, 3b, 3c or 3d riding up an appropriately inserted bolt cam. The four rows of butts, 3a, 3b, 3c and 3d (on different jacks) are at different levels and cooperate respectively with bolt cams A,B,C and D at corresponding levels. By arranging each row of butts in a different set out and operating successive levels of bolt cams at various stages in the knitting sequence, a variety of fabric constructions may be obtained such as a mock rib in which alternate needles knit and intermediate needles tuck, followed perhaps by a different basic construction for the leg. The butts at one level and the corresponding bolt cams may be used for producing tuck patterns at certain feeding stations and butts at another level may be used for the insertion of rubber yarn.

When selective patterning is taking place all the bolt cams A,B,C and D are withdrawn from the needle cylinder, thus rendering the butts 3a, 3b, 3c and 3d ineffective so that the intermediate jacks 3 then merely act to transmit motion between the selecting instruments 4 and the needles 2. It is with the arrangement for this selective patterning that the invention is more particularly concerned.

The selecting instruments 4 are of a conventional type capable of rocking motion about a fulcrum point 4a. They are rocked outwards at their lower end by projecting cams C1 to C6. The raising cams for the instruments 4 are shown at P1 and P6, and as each of the six selecting positions is identical, the following description will refer principally to one only of the positions, viz that of cam P2.

There is a bank of selector cams indicated at SC (one such bank being provided immediately in advance of each of the cams P1 to P6). According to the required pattern, certain of the selector cams SC will be displaced in towards the cylinder and others will be away from the cylinder. The selecting butts 4b of certain of the instruments will be pressed by the cams so that their raising butts 4c will pass behind the raising cam P2. The butts 4c of instruments which are not so pressed or rocked will ride up cam P2 and cause the related needles to clear the yarn below their latches prior to receiving yarn at stitch cam S2. The needles of those instruments 4 not so raised will pass the stitch cam S2 at a low level and miss taking the yarn. The butts 2a of the raised needles descend stitch cam S2 and in so doing return the raised jacks 3 and instruments 4 so that the butts 4c follow the dotted line 6 and eventually rejoin the low level path 7 (shown chain dotted) followed by the butts 4c of the unraised instruments.

With previous patterning mechanisms of the same general character, the butts 4c of the raised instruments rejoin the depressed butts 4c of the unraised selectors and then both sets of butts pass in front of a cam such as C2 by which the depressed butts were brought out for reselection at the next bank of selector cams. According to the invention, however, reselection of the butts 4b is organized to take place earlier than hitherto, and actually takes place immediately after the projecting butts 4c following path 6 rejoin the depressed butts 4c following path 7. This is permitted by cutting away (as shown at 8 in FIG. 1) the face of the raising cam P2 which is adjacent to the needle cylinder thus allowing the rocking cam C2 (for resetting the instruments 4) to be positioned in advance of the rejoining point of the butt paths 6 and 7 so that lowing the joinin of the butt paths 6 and 7.

The cut away aces of the cams P1 P2 etc. are angled at 8 to cam back projecting butts 4c when the needle cylinder is turning in the reverse direction. Cams C1, C2 etc., are likewise provided with a reverse slope CS to permit the tails of the selectors 4 to run in the reverse direction without jamming against edge parts of such cams.

Although the invention is shown as applied to a single cylinder hosiery knitting machine having six feeding stations and reverse knitting cams, it is to be understood that this is by way of example only. The invention could equally well be applied to other types of knitting machines including opposed coaxial needle cylinder machines, the purpose being to provide needle selection patterning means which occupies less space around the periphery of the needle cylinder than have previous patterning mechanisms.

We claim:

1. In a circular knitting machine, the combination comprising a needle cylinder equipped with needles slidable in tricks in said cylinder, rockable selecting instruments in the cylinder tricks and associated with the needles and having raising butts, selecting means to act on the instruments when projected from their tricks to cause particular ones of the instruments to be depressed into their tricks, cam means for raising and lowering instruments not so depressed including a raising cam having ascending and descending slopes and presenting on its inner face a recess at low level below its descending slope, said recess having an end opening into the lower end part of said descending slope and serving to accommodate outward movement of raising butts of depressed instruments not raised by the raising cam, a projecting cam aligned with said recess to project said depressed instruments from their tricks and cause their butts to enter and pass along and out of the said end of said recess in the raising cam, and further selecting means to act on the selecting instruments at the position at which selecting instrument butts emerge from the said end of the recess to join the track of other selecting instrument butts that have passed down the descending slope of the raising cam.

2. In a multifeed circular knitting machine a combination according to claim 1 wherein a complete set of said selecting means, cam means and instrument projecting means is provided at each feeding station and the selecting means at each succeeding feeding station acts on the instruments as soon as the nondepressed instruments have been lowered down the descending slope of the raising cam at the next preceding feeding station.

3. The combination according to claim 1 wherein the raising cam has its inner face formed with a horizontal groove at its back trailing part to form said recess, such groove .being slanted in depth so as to open on to the front (i.e. the outer) face of the cam immediately before the trailing end thereof.

4. The combination according to claim 3 in a machine adapted to perform knitting by reciprocatory as well as continuous rotary motion, wherein the said horizontal groove in the raising cam is formed as a cam slope to engage raising butts on the instruments during the return stroke in reciprocatory motion and a similar return cam slope is formed on the projecting cam. 

1. In a circular knitting machine, the combination comprising a needle cylinder equipped with needles slidable in tricks in said cylinder, rockable selecting instruments in the cylinder tricks and associated with the needles and having raising butts, selecting means to act on the instruments when projected from their tricks to cause particular ones of the instruments to be depressed into their tricks, cam means for raising and lowering instruments not so depressed including a raising cam having ascending and descending slopes and presenting on its inner face a recess at low level below its descending slope, said recess having an end opening into the lower end part of said descending slope and serving to accommodate outward movement of raising butts of depressed instruments not raised by the raising cam, a projecting cam aligned with said recess to project said depressed instruments from their tricks and cause their butts to enter and pass along and out of the said end of said recess in the raising cam, and further selecting means to act on the selecting instruments at the position at which selecting instrument butts emerge from the said end of the recess to join the track of other selecting instrument butts that have passed down the descending slope of the raising cam.
 2. In a multifeed circular knitting machine a combination according to claim 1 wherein a complete set of said selecting means, cam means and instrument projecting means is provided at each feeding station and the selecting means at each succeeding feeding station acts on the instruments as soon as the nondepressed instruments have been lowered down the descending slope of the raising cam at the next preceding feeding station.
 3. The combination according to claim 1 wherein the raising cam has its inner face formed with a horizontal groove at its back trailing part to form said recess, such groove being slanted in depth so as to open on to the front (i.e. the outer) face of the cam immediately before the trailing end thereof.
 4. The combination according to claim 3 in a machine adapted to perform knitting by reciprocatory as well as continuous rotary motion, wherein the said horizontal groove in the raising cam is formed as a cam slope to engage raising butts on the instruments during the return stroke in reciprocatory motion and a similar return cam slope is formed on the projecting cam. 